Many people use communication terminals, such as cell phones and personal digital assistants, to communicate with cellular wireless networks, which typically provide communication services such as voice, text messaging, and packet-data communication to these communication terminals. The communication terminals and networks typically communicate with each other over a radio frequency (RF) air interface according to a wireless protocol such as 1xRTT CDMA, EV-DO, WiMax, iDEN, 802.11, etc.
For example, communication terminals typically conduct these wireless communications with one or more base transceiver stations (BTSs), each of which send communications to and receive communications from communication terminals over the air interface. Each BTS in turn is communicatively connected with an entity known as a base station controller (BSC), which (a) controls one or more BTSs and (b) acts as a conduit between the BTS(s) and one or more switches or gateways, such as a packet data serving node (PDSN), which may in turn interface with one or more signaling and/or transport networks. As such, communication terminals can typically communicate with one or more endpoints over the one or more signaling and/or transport networks from inside one or more coverage areas (such as cells and/or sectors) of one or more BTSs, via the BTS(s), a BSC, and a PDSN.
Communication terminals may also conduct wireless communication using other means. For example, a communication terminal may communicate with a wireless device, such as a wireless router, using a protocol such as 802.11. The wireless router in turn may interface with one or more signaling and/or transport networks. As yet another example, a communication terminal may engage in direct communication with another communication terminal using peer-to-peer communication.